drivehardaz

Since I have access to several competent welders and an extra header for my 1.8 and am being cheap I am looking to build my own header. I need to get an idea of how exactly a 1.8L manifold is setup so that when I fab mine up I have the necessary clearance. I am looking at cutting my existing header just above where the collector is right now and welding in a t4 flange there. How centered does the turbo need to be in relation to #1 and 4 cylinders for clearance on the brake master cylinder and on the front side ac and power steering? How far from the engine am I going to need to be so I dont hit the engine of the fenderwell? Some basic measurements of the drop from the bottom of the manifold flange to the turbo flange parallel to the block would work. A measurement from the inside edge of the turbo flange to the exhaust flange perpendicular to the block would work as well.
I am going to be running a t3/t4 hybrid 57 trim turbo. I am also going to have a piece of metal welded to seperate the pulse as well, if I am going external wategate and I dump from only one side is that sufficient to releive pressure? I am looking to dump off the back edge so I can dump to the exhaust not to atmosphere. I realize with a log type manifold it is centered, if I offset toward the rear of the car by 2-4 inches will I run into issues?

Thanks in advance
Joe

Sirnixalot

it wont work.
the stock header tubing wont support a turbo and will crack
there is no way you are getting a turbo to fit where the collector is
a t4 flange doesnt work for a t3/t4

reuse the flange on the header and get some weldable elbows and t's and get a log manifold made up

drivehardaz

Ok I misspoke with the t4 and should have said t3 flange. I fully intend to brace the turbo, based on a friends car we have a good idea how to support it, I would have braced it no matter what type of manifold. I am really not interested in an ugly log manifold, if anything I would buy an hks or similar tube type manifold. I would prefer to go equal length runners but for first try I want to go this route. I do not intend to weld the turbo flange where the existing collector is. I am looking to cut the header well above that, probably 2 inches above the collector itself and work to blend the four tubes at that point.

Sirnixalot

bracing might do more harm than good depending on the material

when i said it wouldnt support the turbo i did meant weight wise but i also meant that the material itself was too thin to cope with the increased heat and the frequency of the cycles.

weldable elbows are like $5 a pop, you could make a semi equal like the etdracing mani